Venous disorders, especially varicose veins, are extremely common, afflicting tens of millions of Americans. The treatment of varicose veins has always been controversial, because no perfect treatment exists.
There is substantial data indicating that the differences between the veins of varicose people and "normal" (i.e., non-varicose) people are not limited to the diseased veins, but bear as well on the apparently normal ones. In other words, whatever forces are responsible for the conversion of a normal vein to a varicose vein are present and acting upon the apparently normal veins adjacent to the varicose veins on the same leg. It is now universally accepted that no existing treatment will prevent veins which are normal now from becoming varicose in the future.
Above and beyond the fact that the varicose predisposition cannot be permanently cured, the recognizably abnormal varicose veins currently present, toward which all therapeutic modalities are directed, are not easily removed. In certain respects, removal of a varicose vein is like removal of a malignant tumor. Any part of the venous network which is contributing to the varicosity, and which is left behind by the surgeon, can and will give rise to a total treatment failure.
The key word here is "network"--the venous system is a continuous network of connected vessels, and in many instances the distinctions drawn between different veins in anatomy texts are arbitrary. For example, the main deep vein of the leg is called the "popliteal" vein below the knee, and the "femoral" vein above the knee. But there's no discontinuity between these veins--they are the same long tube, half of which having one name, and the other half having another name. Similarly, many veins change names at junctions with other similar sized vessels. But there is no reason why a disease afflicting a named vein will stop at a point where the name of the vein changes.
In FIG. 1, vein 100 is shown as branching into veins 102 and 104. If vein 100 was a varicose vein, and surgical removal of vein 100 were deemed to be the treatment of choice, then the treatment would work if and only if veins 102 and 104 were normal.
Unfortunately, the real situation is that vein 100 might be a visible, palpable vein on the surface of the leg, and veins 102 and 104 might be buried deep in the calf or thigh muscles, or somewhere in the pelvis. If either of veins 102 or 104 is a contributing factor to the varicose condition of vein 100, then failure to remove 102 and 104 along with 100 at the time of surgery will lead to rapid recurrence of varicosity. Suppose, for example, that vein 102 is abnormal. FIG. 2 illustrates how failure to remove vein 102 will lead to recurrent varicosity.
Note that there are numerous small, seemingly insignificant and unnamed veins in the network of vessels connecting and surrounding 100, 102, and 104. (FIG. 2A) After vein 100 is removed, the pressure formerly exerted on it by vein 102 now bears on the small unnamed vessels of the network. (FIG. 2B) In as short a time as 3-6 months, one or more formerly small vessels in the network will have undergone varicose degeneration, and the patient will return to the surgeon looking as if the operation had never been done. (FIG. 2C)
FIG. 3 illustrates a slightly different way in which incomplete surgery can lead to recurrence. The best-known and most frequently treated of all veins subject to varicosity is the greater saphenous vein 106. The segment of the venous system bearing this name begins at the medial (inside) ankle, just in front of the medial malleolus (inside ankle bone), and extends along the inside of the leg all the way to the groin, where it joins the femoral vein 108, at a point called the saphenofemoral junction. There are a few small vessels, referred to as tributaries, entering the saphenous vein 106 just below this junction. The actual number of such tributaries is variable, generally numbering between 3 and 8. (FIG. 3A) If the surgeon cuts the saphenous vein 106 below these tributaries, (FIG. 3B) one or more of them will dilate and the patient returns in 1-12 months with a new varicose vein that looks just like the old one that was removed. (FIG. 3C).
Since 1851, varicose veins have been treated by injection therapy. This treatment is now called "sclerotherapy". The medicines injected are called "sclerosing solutions", or simply "sclerosants". All the early attempts had unacceptably high failure rates, largely because of the lack of attention to the sort of anatomical features outlined above. In the case of the greater saphenous vein, for example, a varicose vein might protrude through the skin at two or three places as shown in FIG. 4A. The vein, however, actually runs all the way up from the ankle to the groin as shown in FIG. 4B.
The old-time injectionist or sclerotherapist would inject a sclerosing treatment solution at each of the blue bumps 110 and 112 (FIG. 4A), totally ignoring the top of the vein where all those tributaries 114 are: (FIG. 4B) For reasons illustrated in FIGS. 2 and 3, this treatment usually failed within a year or two. The sclerotherapist's answer to this problem, in the early days, was to insist on annual check-ups, at which time the recurrent varicosities would be re-treated. There would be no end to the annual checkups.
The surgical approach to varicosity is the stripping operation, invented by Charles Mayo at the clinic bearing his name at around 1900. The original stripping operation proved, on long term followup, to have roughly a 50% failure rate. It was 30-40 years before surgeons figured out what was wrong. The main problem was the tributaries. Mayo did not realize the importance of cutting the saphenous vein 116 precisely at its junction with the femoral vein 118, at a point above the highest of the tributaries. FIG. 5 illustrates the proper 120 (operation is successful) and improper 122 (operation fails) locations for this cut.
The major achievement of the post-Mayo vein stripping researchers was the realization of the importance of the absolutely flush saphenofemoral ligation and division, with simultaneous ligation of all the tributaries.
In spite of this increased meticulousness of varicose vein surgery, the existing procedures still fail to bring about even short-term remission from varicosity in 10-20% of cases. Efforts to improve on these figures with a variety of more aggressive and mutilating operations, developed and tested between 1940 and 1960, were uniformly unsuccessful, and today, nearly a century after the invention of the Mayo stripping, it remains in only slightly modified form the treatment of choice for severe saphenous varicosity.
The reasons for the high failure rate with surgery (the failure rate with injection sclerotherapy being even higher) are complex and multifactorial. The known reasons are listed now:
1. The deep veins may be diseased. In the presence of severe deep venous disease, rapid recurrence of surface varicosity cannot be prevented. PA1 2. Varicosity may be associated with multiple small arteriovenous malformations. Surgical interruption of hundreds of tiny arteriovenous communications is generally not feasible. PA1 3. The saphenous vein may be double, triple, or even quadruple. When a duplicate saphenous vein is present, it is usually quite small, and is likely to be missed during surgery. But after the primary saphenous is removed, the duplicate will rapidly enlarge. PA1 4. In spite of the best efforts of the surgeon, a tributary of the saphenous vein might be missed. PA1 5. A varicose vein which appears, at first glance, to start at the groin, may actually start in the pelvis. As explained above, failure to treat the pelvic component inevitably leads to recurrence. PA1 6. A varicose vein which appears to be a result of disease of the short saphenous vein, a vein which extends from the back of the knee (popliteal space) to the ankle, may actually originate deep in the muscles of the calf, or may enter the muscles of the thigh and terminate somewhere far removed from the popliteal space. If these anomalous veins are not taken into account, recurrence is inevitable.
The present invention is designed to overcome the shortcomings of available treatments, especially with respect to the problems listed above. The first two items on the above list cannot be overcome by any forseeable technological advance, but the last four are well known and frequent causes of treatment failure; causes which can be avoided if the treatment takes advantage of the special characteristics of the invention.